Little Things
by th3f4113n
Summary: 'Of course you would think that. You never lived in the wild. You don't know what it's like to be free.' AU. Shark!Erik. Lab rat!Charles. Cherik.
1. Like any other story

**Little Things**  
XMFC. Cherik? (kind of, lol). PG13. 1257+ words (for this chapter). AU. Shark!Erik & Lab rat!Charles (with their powers intact in some way). I should probably warn for **crack **in the sense that this idea is cracktastic, **angst **due to the non graphic experiments taking place, and probably **violence **later on. (What the fuck? Lmao.)

I got the idea from the movie _Despicable Me_'cause that guy had a pet shark and I thought it was really cool how that shark swam around and was biting people.

Also, please do not take this too seriously, um. I'm taking a lot of liberties with this. Also, single quotations mean talking through thoughts. I didn't want to use italics too much.

Anyway-

-o-

_'Of course you would think that. You never lived in the wild. You don't know what it's like to be free.'_

-o-

I: Like any other story

Once upon a time, there was a lab rat named Charles and a pet shark named Erik. They were kept by a peculiar man, Sebastian Shaw, who had an affinity with intelligent and dangerous animals. The first one to be bought and brought home was Erik and he was rather surprised that he actually had a vast amount of space to swim in— the entire underground floors of Shaw's mansion.

At first, he didn't really know why he was there other than the fact that he was being kept as a pet, but that soon changed when he began exploring the underground; there were certain lidded holes, holes that he could jump out of if he so wished and then it was made clear that he wasn't just a pet, but a guard shark of sorts. Shaw didn't want any intruders, apparently.

(For what reason? He didn't know.)

To _some _extent, he was fine with that. He was very good at what he did, being a predator, stalking and striking and killing his prey with uncanny efficiency. Nature had bred him for it. He was perfection.

He could only tolerate Shaw when Shaw fed him live, breathing things. It made the hunt all the more thrilling; he wasn't being wasted in this underground space—what the humans would probably call an aquarium, an abnormally large one at that.

Otherwise, he detested this strange man. This place could never compare to living back in the ocean and there wasn't a moment where he didn't think about escaping. If only he had feet like a human or even had some way to communicate with them. Then he could tell them how he'd like have them for lunch if they didn't send him back to the ocean.

In the meantime, he busied himself with the routines of this mansion. He'd swim around, trying to sense if there were any intruders for a light snack and actually, there were quite a few. They really shouldn't have bothered trying to walk on the floors. It was easier to hear their movements, their footfalls and smell their heat permeating from their skin and when he could scent just a hint of blood, it made him all the more excited to kill them.

Ultimately, the arrival of the lab rat had broken and changed those routines.

The lab rat, or Charles, as Shaw liked to call him, was different. From the glass floors, Erik could see him. He was a small white furry thing, but instead of having red eyes like normal lab rats, his eyes were blue, freakishly blue, like the very ocean itself. Erik found that annoying.

Charles was a lab rat in a sense that his owner, _their _owner rather, not only played tricks with him to test his intelligence (and he was very intelligent, Erik could see that, as Charles whizzed through each miniature maze, chewing on cheese by the end of it), but Shaw would also literally experiment on him, dousing and injecting him with dubious-looking liquids.

Erik detested Shaw a little more because of that; somehow, it reminded him of the fact that he had been taken away from his home. Shaw had no right to do that to him or to Charles.

After one grueling experiment, honestly, Erik was surprised that Charles was still alive, huddled up against one of the corners of his rectangular rat cage.

Erik simply stared at him, out of grim amusement and curiosity more than anything else. Such a fragile little thing, still going so strong.

Eventually, Charles noticed him.

The rat turned around and stared back at him with his bright blue eyes. The rat blinked once. Twice.

'Is there something on my face?'

Erik jumped, bumping against the glass floors. Where did that voice come from? He looked around, trying to sense anything strange in his watery surroundings, but there was nothing. The voice had come from inside his head. How in the world?

The rat looked just as surprised and confused. They were of different species; it wasn't like they could communicate. Erik simply saw him as a creature not even worth to be called a prey.

'Did I think that out loud? I'm very sorry.'

'It's you!' Erik realized with a gasp, his tail whipping against the natural flow of the waters in agitation. He stared at the rat again, trying to figure him out. 'How is that possible?'

'I don't know,' said the rat in a self-depreciative tone of voice. 'It must have something to do with those injections.'

'I suppose. They don't look like fun,' Erik said, sharing his particular taste in black humor.

There was an awkward moment between them then, neither creature knowing what to say next, but that eventually passed as Charles spoke to him in his mind again.

'You came from the ocean,' Charles assumed, changing the subject abruptly. He was looking him over— well, what he could see of him anyway. Charles would probably only see his grey and white face, along with his snout and his many, many sharp teeth. Erik rather liked that. Charles only chuckled. Did Charles pick up on that?

'Yes,' Erik deadpanned. 'Where else would I have come from?'

'Well, you could have been bred in captivity,' Charles suggested, 'like I was.'

'What does that even mean?' Erik asked, not liking this one bit.

'Animals who weren't born in the wild,' Charles said with a shrug. 'I learned many things about humans this way, being passed from one owner to the next.'

'And why is that? Were you a bad _pet_, Charles?' Erik inquired, smiling and flashing him all of his teeth, hiding this sinking feeling of horror at the information he'd received through the tactics of intimidation.

'Oh no,' Charles said, shaking his little head. He didn't look fazed at all. 'I outlive them.'

There was a moment of silence. Erik thought about this for a while. So somehow, Charles could talk to him in his mind and somehow read his thoughts and really, he should be very disturbed about that, but then there were different animals who had different ways of communicating. Why shouldn't this be any different?

'You're not an ordinary rat, are you, Charles?' Erik wondered. 'For such a small thing, I don't think rats are supposed to live that long.'

'They don't,' Charles admitted. 'That's why this Sebastian Shaw has decided to acquire me, to experiment on me and figure out how I tick. It's strange. Most of the humans who have taken care of me in the past are very good and don't mean any harm—'

Erik glared at him. 'Of course you would think that. You never lived in the wild. You don't know what it's like to be free.'

'Perhaps,' Charles said thoughtfully, 'but maybe things will get better once he's done with his experiments.'

Erik sighed heavily. 'How do you know that?'

'Humans get bored very easily,' Charles said. 'He'll probably buy another pet once he tires of me.'

'What will you do when he finds out that you can talk the way you do now?' Erik asked, frowning. 'Did you think about that?'

'There won't be a _when_,' Charles said carefully. 'I'm not even sure myself how I'm doing this.'

'You better figure it out soon,' Erik said, hearing those familiar footfalls. They were different from the light and hesitant steps of the fearful intruders. The man walked with a solid, focused purpose in life. What that purpose was, Erik didn't know. 'He's coming.'

'Oh dear.'

To be continued?

-o-

A/N: Oh boy, how in the world did this happen? Anyway, I started writing this because I was going through an existential crisis with my life and I wanted to write something silly to make me feel better. Other than the movie, I fucking adored anything with Erik as a shark and Charles as a rat, so yeah, this fic was inspired by those fanarts on tumblr too.

So, anyway, I'm writing this out of my ass, so it's likely that I'm going to edit this over and over again to avoid continuity issues once I write the rest of this and hopefully, _hopefully _finish it. I also hope to update this every Tuesday, because I adore Tuesdays. Tuesdays make me happy.

I'm also aware that there are probably a lot of stories similar to this, but I've never written one, so this is new to me, personally. Hehe.


	2. Sebastian Shaw

**Little Things**  
XMFC. Cherik. PG13. 1300+ words (for this chapter). AU. Shark!Erik & Lab rat!Charles (with their powers eventually). Crack/humor. Angst. Non graphic experiments. Possible violence and gore.

-o-

II: Sebastian Shaw

And so there he was—Sebastian Shaw. He was a tall, intimidating man, with his long white lab coat, and his tray of many syringes and ironically, a little red bag with a picture of small light brown blocks of mixed food on it—for Charles, most likely.

Erik watched Shaw warily, with a barely suppressed urge to kill, as the man walked over to them and stood in front of the rat cage. He was smiling a cryptic smile. He set the tray aside and unlocked the cage. He grabbed the bag and opened it, pouring the food into the rat feeder.

Erik turned his eyes to Charles. The rat was staring at the feeder, wrinkling his nose, probably trying to scent the food. Despite the grainy noise of the food going into the feeder, a dark, foreboding silence had inundated the white room. Erik _truly _hoped that Charles wouldn't do anything stupid like thinking out loud or whatever it was that he had done with Erik just a few moments ago.

Then Shaw began to talk.

"Hello Charles," he said, looking curiously at the rat. Charles stayed huddled in his little corner of the cage, refusing to move. "You don't seem to want to eat today, hmm?"

He reached out and stroked the pad of his finger on top of Charles' head. Charles only continued to stare at the feeder. It looked as though Charles was trying to concentrate on something. Maybe the rat had a plan. Maybe he had already figured out this strange new way of communicating.

Shaw gazed at the syringes for a moment and then back to Charles. "Maybe I've done enough for today." There was that cryptic smile again. His cold blue eyes had a strange glint on them. "Wouldn't want you to die too soon, Charles."

And just like that, he locked the cage, picked up his tray and walked out of the room, with those damning steps echoing throughout the endlessly long haunting hallways. It was strange. Erik had been watching Shaw and then Charles just now, but save for Charles' name, he didn't understand any of the words that had come out of Shaw's mouth.

He'd seen that mouth moving, those hands and fingers feeding and _petting _Charles, those cold blue eyes looking thoughtful at the syringes and just thinking about it all was causing his tail to lash out against the waters again. With Shaw gone, however, the foreboding silence seemed to have been lifted like a mist clearing out as the sun shone upon a beach, though a certain stillness was flowing into the room now, giving it a temporary sense of tranquil.

Charles let out a soft sigh of relief. 'He didn't hear anything.'

Erik grinded his teeth together. 'You think so?'

Charles looked down at Erik and smiled. 'I _know _so.'

'Oh?' Erik inquired, narrowing his eyes into slits. 'How did you do it then?'

The rat shrugged. 'I just thought really hard.'

'That sounds stupid,' Erik said frankly.

'Thank you for your honesty,' Charles said with biting sarcasm, 'it's deeply appreciated.'

'You're welcome,' Erik said gruffly. There was another awkward pause between them, but this time, Erik chose to be the one to break it. 'This is serious, Charles. If he finds out—'

'You worry too much,' Charles said mildly, smiling again. 'I didn't want him to hear and so I didn't talk. I willed myself not to say anything.'

Erik gasped. He must looked appallingly silly now, with his mouth hanging wide open, even with those glittering sharp teeth of his. 'It can't be that simple— just from the power of pure will?'

Charles didn't say anything for a moment, mulling over something, it seemed, as he stood on his hind legs. 'No, I _really _didn't want him to hear—because you were right. I wouldn't know what to do with myself if he _did _find out about this. He'd probably stab more of those needles into me, so I calmed my mind and thought of nothing.'

'You were afraid,' Erik said slowly, realizing it. 'Interesting.'

'_What_?' Charles asked, looking scandalized, which was hilarious for a rat, with all his fur prickling out like a puffer fish. 'Well, not all of us look like— well, like a _shark_, you know.'

'But it worked, didn't it?' Erik said thoughtfully. 'Fear can be its own strength.'

If you feared something, you hated it. He'd already heard the stories of domesticated animals, of _pets _from the smaller fishes in the ocean, and to think that he was one now… He wasn't stupid. He knew that sharks were the greatest predators of the sea, but the kind that was greater than they, as much as it angered him, were the humans.

(But it was only for now, just for now. )

He remembered how they'd fished him out, how he'd thrashed, gasping, trying to breathe, biting any limb he could reach, but to no avail. Like Charles, he'd been injected with something and his will to fight and _kill _had been washed out of him. It had been replaced by something else, that familiar sinking, sickening feeling of horror, as he'd stared at the man who became known as Sebastian Shaw, not knowing what was going to happen to him, not knowing how he would survive, drowning in that grasping feeling of uncertainty. Fear.

But it kept him going, that fear, that hatred, stopped him from killing Shaw immediately when he realized that at the very least, Shaw was feeding him. It wasn't easy, biding his time, trying to control himself, but he was a predator. He knew when to strike and how.

He turned his back on Charles. He had things to think about. A while ago, he wondered if he could have human feet. That obviously didn't work out. But then there was Charles and his strange ability to speak into his mind. He could do the same with the humans. But then, that was the point, wasn't it? If he talked to humans, then the humans would find out about Charles and who knew what they would do with him. It was why this particular encounter and the future encounters with Shaw was and always would be especially dangerous.

'What?' Charles asked doubtfully. 'What are you talking about? Where are you going?'

'Going to stalk Shaw,' Erik said. 'I need to know what he's doing right now.'

Charles gasped. 'You're not going to kill him, are you?'

Erik laughed. It was a horrible sound. 'Not yet.'

Charles let out a loud squeak of dismay. '_What_?'

'You worry too much,' Erik said, using the same words against him. 'Go to sleep, little Charles. Rest.'

'Don't patronize me,' the rat snapped. Erik chanced to look back and once again, he laughed. Charles was actually baring his teeth at him. It was strangely endearing.

'I wasn't,' Erik said softly. 'In case you haven't noticed, I've been watching you for a while now. You've already been through a lot, especially today...'

'Yes, I have noticed,' Charles said with a huff. 'Then I wondered whether Shaw was feeding you right because personally, I doubt I'd taste very good to you.'

Erik chuckled in grim amusement. 'Oh, at the very least, he feeds us right. Is that the real reason why you think he'll eventually stop what he's doing? Over time, he'll kill you. I think he almost did today. I hope that you're just as aware of it as I am.'

Charles grimaced. He looked away for a moment, seemingly lost in thought, and then turned back to Erik. 'He's not like the others…' he paused and then sighed as though to calm himself again. 'But thank you for your concern, my friend. That, I actually really appreciate.'

Erik gave him a puzzled look. _Friend_? He simply didn't want Charles to go through what he had, being kept here as a _pet_, but he supposed that it was already too late for that.

Once again, he turned around. 'Sleep, Charles.'

Finally, he swam away.

To be continued?

-o-

A/n: This fic is starting get serious. Lmao. Uh, this fic is a lot darker than it looks now, I guess. I should probably warn for that.

Lmao, I was actually looking up stuff for this, like how to take care of sharks and rats. Maybe I should get a rat someday. Hmmm.

Next chapter's gonna feature Charles' pov, finally. I wasn't able to get to him with this one 'cause lol, like Fassbender, Erik pretty much stole the show. *shifty eyes*


	3. Humans

**Little Things**  
XMFC. Cherik. PG13. 1600+ words (for this chapter). AU. Shark!Erik & Lab rat!Charles (with their powers eventually). Crack/humor. Angst. Non graphic experiments. Possible violence and gore.

-o-

III: Humans

Humans were many things, Charles thought.

They were arrogant.

An image of a blond teenage youth crossed his mind then. The blond had considered himself tough because he'd lived such a large part of his life alone, locked in juvenile detention. They'd given him Charles, thinking that somehow taking care of a pet would rehabilitate him, but in the end the boy hadn't taken care of him at all, didn't read the instructions, couldn't even deliver Charles' food even though it'd been handed to him, just because the boy had thought that they were just mocking him, sending him a pet— _seriously, what the fuck_, the blond would say.

They were stupid.

Another boy, a redhead, reckless or careless—honestly, Charles had been nervous about that one. He'd leave Charles in his room all the time and barely played with him and would hang out with his friends and when he'd come back, he'd listen to all these rock songs, screaming his lungs out and good god, did he have such a _voice_. Any louder and the boy would probably break the windows.

They were ignorant.

A girl this time, blonde and delicate. She had taken care of him well actually, fed him right at least, but then she was quite peculiar herself, had an obsession with diamonds and she'd decorate his cage with said diamonds. Sometimes, she'd even bring these cute little dresses, fit just for his size and don it all on him and why oh why had she thought that was a good idea?

Yes, they were all these things, Charles thought, as he settled down, curling around himself and getting ready to rest and perhaps sleep, his tail looping around his body as though to protect himself. But, Charles knew, while the humans were all these things, they were not— at least, not intentionally — evil, maliciously evil.

When he'd told the shark about the people taking good care of him, those three in particular were the exceptions to the rule.

And yet, there was Sebastian Shaw.

Oh, Charles had no idea what to think about Shaw. His last owner, who went by the name of Hank McCoy, had been forced to give him to Shaw due to some meddling in his line of work. But Charles—he was a very old rat, who'd already seen too much and perhaps he thought himself a bit arrogant too, assuming that in the end, it would all blow over soon and he could go back to moving from one home to the next, outliving each of his owners.

Personally, he had no idea why he lived so long. That shark was right. He should have been dead by now, but if there was anything to be learned from life, it was that nature was a very interesting, strange creature herself, providing him with a way to survive. But then, that was why the scientists had gotten hold of him in the first place, trying to discover something in his blood.

A means to live longer.

Immortality.

So no, Shaw wasn't the first one to jab things at him, to run tests, to take a sample of his blood, but he was the most persistent and excruciatingly painful about it. Charles could get used to the pain. It was easy to numb himself. But it was never easy trying to cope with the side effects. Apparently, he could read minds now. So, he supposed, judging from what he'd seen on the TV shows, on the cartoons that some of his previous owners had watched, he was, well, technically a telepathic lab rat.

Which was quite a useful thing.

If he had to be honest with himself, he'd already known about this, just hints of it subconsciously, having a six sense of self-awareness, but he'd been keeping his thoughts to himself for a while, trying to calm down. Before, in the beginning of everything, from the first moment he'd been born, all he cared about was surviving and food and if he had a mate at the time, making baby rats.

But now, he was stuck in this new rat cage, with a shark lurking beneath the floors and though the shark —really, he should just call him Erik —seemed to know his duties, guarding Shaw's mansion by feeding on its many, many intruders, he doubted that Erik was doing it out of the goodness of his heart. The creature was a shark, born and bred to be a predator; his instinct was to kill.

(Erik had yet to kill Shaw, however. It was something that Charles was grateful about.)

It didn't seem to stop Charles from reaching out to him though, at least accidentally. He'd been testing himself, just thinking, trying to imagine the mind like the mazes he'd scurried in and out of and was pleasantly surprised, but also confused that it had actually worked.

Thinking out loud. Those words described what he'd done the best and he was all the more horrified at the thought of Shaw might knowing about this, hence the words he'd spoken with the residential shark. He'd meant it all, kept his mind as clear as an untouched pond to keep his thoughts out of everybody's heads because he didn't know just how much control he had over it. It wasn't something he could risk.

But what was his plan now—did he even have a plan in the first place? If anything, that shark didn't seem too keen to be in the mansion. Obviously, the shark, being born in the ocean, in the wild had a different perspective on the humans. If they were to escape Shaw, how would they go about it?

So far, he could only read minds and talk to Erik with it. He could probably talk to the humans as well, but Shaw was the only person to ever visit them. If Erik were to stop mauling at those so-called intruders, then he could probably test himself again and see whether he could do anything else with this new ability of his.

He liked the sound of that. With that thought, he closed his eyes and finally went to sleep—well, he _tried _to sleep, with a shiver.

It was going to be a long, long night.

-o-

'You look like you didn't get any sleep at all,' Erik said with a snort. 'Did you even eat?'

Charles was leaning on the little white bars of his cage, gripping the bars with his paws. He shook his head at the shark staring up at him. Truly, Erik was such a scary, scary thing. Big body. Large mouth. Big sharp pointy teeth. He remembered what he'd thought about yesterday. Those teeth could shred him to pieces. But Charles wasn't afraid. It might have something to do with his eyes. Those strange eyes. They weren't black.

They were as green as the sea.

'It was cold,' Charles said with an irritated sniff. 'And I wasn't that hungry.'

The shark stared at him again, not at all amused. That was another thing. He didn't know creatures like Erik could be so… concerned, but Charles was flattered just the same. He decided to change the subject and focused on Erik instead. 'So how did it go with stalking Shaw?'

The shark looked disgruntled. 'It was stupid. He was looking over things like the usual.' There was a moment of silence. Erik narrowed those green eyes at him. 'But have you decided whether or not you're going to let him kill you?'

Charles made an annoyed chattering noise at him. Erik looked like he would have laughed. Hmm. He hadn't been thinking about that. He'd been thinking about many things, about the humans, about the side effects of Shaw's experiments on him, but he supposed that in a way, he _had _made a decision.

'I am _not _going to let him kill me,' Charles said stubbornly, releasing his grip on the bars and standing on his hind legs. 'But I don't know if escaping is that simple.'

'Well, you're the lab rat,' Erik said, his mental voice dripping with sarcasm. 'You'll figure something out.'

'What do _you _think?' Charles asked.

'I have my limitations,' Erik said. 'The entire underground floors of this mansion are the only places I can swim in. I doubt they lead to the ocean. I don't even know how far we are from the ocean.'

'We're quite far, I think,' Charles said with a sigh. He held onto the bars again, a little more tightly than he should this time, feeling a strange sense of loss. Erik was right. He didn't know what it was like to live in the wild. It sounded dangerous, but alluring all the same. He'd been too used to people handling him. What would it be like to live freely?

'So now what?' Erik asked again. There was a sudden movement below and Charles had caught a glimpse of his long tail whipping in impatience.

'Try to let the intruders in for a change,' Charles said with mirth.

'But that's my dinner,' Erik said as though that explained everything.

'I think you know as well as I do that there are reasons that Shaw has intruders.'

'Of course,' Erik said and for a moment, the shark turned to the side as though to check for something before looking up at Charles again. 'Whatever he's doing in this place, it's _not _right.'

'So let them in,' Charles said, trying to reassure him. 'And we'll see what I can do.'

'Fine,' Erik said. 'If it backfires, it will be on you.'

'Must you always be so— you are one pessimistic shark,' Charles said, mildly amused now, wrinkling his whiskers.

Erik snapped his jaws at him in reply, but Charles could see the same emotion he felt in those eyes, gleaming lightly.

To be continued?

-o-

A/n: Lots of things happening next chapter, lots and lots of things. It'll be longer, hopefully.

Yes, the cameos - Alex, Sean and Emma.

I was curious so I did some more research on pet rats. Apparently, they don't have to be nocturnal since they're domesticated rats.


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